Mimi, Papa, and their grandchildren, Christina and Grant are uber-excited to visit the famouse Neuschwanstein Castle in Bavaria, Germany!. They call it the "Crystal Castle." The excitement begins as soon as the Mystery Girl lands and Grant finds a map -- but where does it lead??? Follow the kids on their amazing adventure through cool underground caves, towering turrets, and the sights, sounds and tastes (yummm!) of Oktoberfest!